1Portion the chicken and place it in a pot with bay leaf, salt, and pepper, pour in the chicken stock and water, then simmer until the chicken is cooked through and tender.
2Remove the chicken and reserve the broth, then remove the bones and shred the meat once cool enough to handle.
3Heat the annatto oil, then lightly toast the minced garlic, add the onion and chopped celery, stir in the shredded chicken, and pour in the reserved broth.
4Season with fish sauce and black pepper.
5Place the annatto seeds in a fine-mesh strainer and dip them into the simmering soup, stirring gently until the broth turns a vibrant reddish-orange, then remove the seeds.
6Add the sotanghon noodles and cook until they begin to soften, follow with shredded Chinese cabbage, julienned carrots, and boiled quail eggs, and simmer until the vegetables and noodles are cooked through.
7Ladle into a bowl, finish with chopped spring onions and crispy garlic, and serve hot.